The primary goal of the newly proposed Transgenic and Chimeric Mouse Facility (TCMF) is to provide a reliable service to members of the University of Pittsburgh Cancer Institute (UPCI) and to others in the University of Pittsburgh scientific community. This service includes the generation of new transgenic and knockout mouse lines, derivation of existing lines via transfer of pre-implantation embryos, cryopreservation of mouse embryos. The TCMF uses state-of-the-art technologies and has staff with the technical expertise to provide these services. Another important aim of the TCMF is to provide consultations with UPCI investigators to assist in the design of experiments to modify the genetic composition of mice. These experiments are primarily transgenic and targeted mutagenesis experiments (knockouts and knockins). The consultations focus on the efficient design of DNA plasmids, containing transgene and gene targeting constructs, to ensure the success of an investigator's in vivo mouse experiments. As part of this assistance, the TCMF can provide a variety of different plasmids to ensure the accuracy of the DNA constructs. Finally, the TCMF will provide an education and training service to investigators wishing to learn and incorporate transgenic and gene targeting technologies into their own laboratories. Technologies provided There are five specific technical services that the TCMF provides to investigators: Pronuclear microinjection (PNM) ES cell electroporation (ESE) ES cell injection (ESM) Line derivation (DER) Embryo cryopreservation (CRY)